The Satellite of Procyon

Abstract

THE announcement in the Astronomical Column of NATURE for November 19 (p. 62), of the discovery of a close companion to Procyon by Prof. Schaeberle, with the 36-inch telescope of the Lick Observatory, will be extremely interesting to those who know anything of the history of the investigations which have been made as to the cause of the irregularity in the proper motion, of Procyon observed by Bessel in 1844, and Mädler in 1851. Following up their observations, Dr. Auwers in 1861 computed an orbit on the assumption of a circular motion in a plane perpendicular to the line of sight, round a point about 1″˙2 distant, having a period of about 40 years, the position angle being about 90° for 1873, and this, with an assumed motion of about 90° per annum, would make the present angle about 300° for the hypothetical companion.